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Biomedical subjects

A J Van Loon

Publications and source records attributed to A J Van Loon.

8 recordsLinked to original sources
PubMed1995

Detection of fetomaternal haemorrhage associated with cordocentesis using serum alpha-fetoprotein and the Kleihauer technique.

Fetomaternal haemorrhage (FMH) was studied after 46 cordocenteses. alpha-Fetoprotein (AFP) concentration and Kleihauer staining of maternal blood, taken both before and after the procedure, revealed increases in AFP values of more than 40 per cent in 30 per cent of the patients examined; fetal haemorrhage of more than 0.25 ml was detected in 46 per cent of the cases by the Kleihauer test. In the second trimester of pregnancy both techniques are comparable, while in the third trimester the Kleihauer technique appears to be more sensitive in detecting FMH after cordocentesis. An anterior position of the placenta is a risk factor for FMH.

Cordocentesis↗
PubMed1995

In utero diagnosis and treatment of fetal goitrous hypothyroidism, caused by maternal use of propylthiouracil.

A fetal goitre is a potentially dangerous phenomenon because of mechanical obstruction and possible fetal thyroid function disorders. In this report we describe a patient with Graves' disease diagnosed in early pregnancy and treated with propylthiouracil, which resulted in a large fetal goitre and fetal hypothyroidism. The diagnostic problems are discussed and we focus on the need for fetal thyroid hormone serum evaluation. The only reliable way to obtain information about the fetal thyroid status is percutaneous fetal umbilical cord blood sampling, since amniotic fluid levels do not properly represent the fetal thyroid function. Fetal hypothyroidism can thus be diagnosed in utero and treated with intra-amniotic injections of thyroxine. The recommended dose and frequency of injections are only based on a few case reports and for that reason we performed a second fetal blood sampling 1 week later to evaluate our therapy. Weekly intra-amniotic injections of 250 micrograms of thyroxine seem to be sufficient to reduce a fetal goitre and give a normal thyroid hormone level.

Adult↗
PubMed1994

Socioeconomic status and breast cancer incidence: a prospective cohort study.

BACKGROUND: To gain more insight into the relation between socioeconomic status (SES) and breast cancer risk, we have studied that association, before and after adjustment for traditional risk factors for breast cancer, in a prospective cohort study on lifestyle and cancer that started in 1986 in the Netherlands amongst 62,573 women aged 55-69 years. METHODS: At baseline, data on SES, diet, reproductive factors and other covariates were collected by means of a self-administered questionnaire. For data-analysis a case-cohort approach was used. After 3.3 years of follow-up, 471 incident cases were available for analysis. RESULTS: We did not find a higher age-adjusted risk of breast cancer for those with a higher level of education (RR highest/lowest level of education = 0.94, 95% confidence interval [CI]: 0.63-1.39, trend-P = 0.15). Although upper white-collar workers had a slightly higher breast cancer risk than blue-collar workers (RR = 1.16, 95% CI: 0.83-1.62, trend-P = 0.34), women with a profession of higher social standing did not have a higher risk (RR highest/lowest social standing = 0.73, 95% CI: 0.24-2.23, trend-P = 0.86). Additional adjustment for traditional risk factors did not alter the association between SES and breast cancer risk. CONCLUSIONS: We did not find an association between SES and breast cancer risk. This is not in agreement with studies conducted in other European countries and North America.

Aged↗
PubMed1991

Alpha-fetoprotein in fetal serum, amniotic fluid, and maternal serum.

In order to gain more insight into the association between alpha-fetoprotein (AFP) and fetal chromosomal disorders, especially Down's syndrome, we measured AFP in fetal serum, amniotic fluid, and maternal serum at cordocentesis. We compared the concentration and gradient of AFP in these three compartments. Our data confirm earlier findings on second-trimester fetal serum AFP concentration. The results indicate that low maternal serum AFP in pregnancies with fetal chromosomal disorders could result from an impaired fetal kidney function as well as from impaired membrane or placental passage of AFP, rather than from reduced fetal AFP production.

Amniotic Fluid↗
PubMed1982

Loss of pesticides from patches used in the field as pesticide collectors.

Patches of fabrics exposed to pesticide spray formulations lost substantial quantities of the chemicals within four to six hours. Fabrics were cotton or 1:1 cotton-polyester blends, knitted or woven, unfinished or finished. Pesticides used were parathion, malathion, and dicofol. Parathion loss following exposure to spray formulations was dependent on fabric type, finish and their interaction, while a less extensive loss of dicofol depended on none of these. Deposition and retention of pesticide-bearing particulates appeared to depend on mechanical restrictions related to fabric weave and on the electrokinetic potential of fabric surfaces.

Agriculture↗
PubMed1977

DDT and DDE in the blood and diet of eskimo children from Hooper Bay, Alaska.

An analysis of the levels of DDT and DDE in the blood of some Alaskan Eskimo children and in the fat of some local marine mammals taken for food suggests that the children's pesticide burdin is only modestly lower than that of other American children. Authors suggest that some other food source, perhaps packaged food, supplies a portion of the dietary chlorohydrocarbon pesticide.

Adipose Tissue↗
PubMedDate not supplied

The anatomical substrate for a difference in surgical approach to rectal cancer in male and female patients.

This review emphasizes' gender related anatomical differences warranting a difference in surgical approach to the problem of rectal cancer in men and women. Differences in the anatomy of the bony pelvis, the pelvic viscera and the lymphatics of the rectum, inspired the authors to extend the margins of the rectal resection in the anterior plane in female patients. Between 1978 and 1992 a rectal resection was carried out for cancers confined to the pelvis in 158 patients. Of these patients 152 were available for review, 95 male and 57 female. In 24 out of 57 female patients extension of the rectal resection towards the genital tract by en bloc excision of posterior vaginal wall and/or uterus was considered necessary to be confident about obtaining tumour free margins. After a median follow-up of 8 years the risk of local recurrence and cancer related death were significantly lower in female patients.

Female↗